0 . c r as s o 1 ame 1 1 at a 
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ing are nearly equal in diameter, and are nearly, if not quite, 
as advanced in development* In other forms it is fixed to four 
cycles In six systems; whilst in some there are three cycles in 
some systems, and only two in others, the corallum being large* 
The form which I consider typical of the species has four 
perfect es^cles in six systems; hut in some corallites the rudiment- 
ary sixth and seventh orders of a fifth cycle exist. The 
specific characteristics — the thick and great development of the 
septal laminae at their wall-end, and the more or less linear, 
hut entire, conditions of their internal parts -- are seen in all 
these forms, in the primary, secondary, and tertiary septa, 
according to the relative septal arrangements * In some corallites 
v/ith a low septal number, the primary septa alone are thus 
characterized; and as the higher cycles are seen, 30 the secondary 
and tertiary septa become enlarged and resemble the primary* 
The septa of the higher orders are either linear throughout or 
slightly enlarged at the wall; and as they approach, the tertiary 
or quaternary, as the case may be, they are seen to become more 
